1 // PR c++/91923 - failure-to-SFINAE with class type NTTP in C++17.
2 // { dg-do compile { target c++11 } }
3 
4 template<typename T>
is_integral_(...)5 constexpr bool is_integral_(...) {
6     return false;
7 }
8 template<typename T, T = 1>
is_integral_(long)9 constexpr bool is_integral_(long) {
10     return true;
11 }
12 
13 static_assert(is_integral_<int>(42), "");
14 static_assert(!is_integral_<void>(42), "");
15 
16 struct S {};
17 static_assert(!is_integral_<S>(42), "");
18